1. Field of the Invention
The present invention relates to a junction terminal and a connector accommodating the junction terminal. The junction terminal connects a pin terminal fitted on a case of an electric instrument with a receptacle terminal of another connector used, for example, for connection of a wiring harness.
2. Related Art
An automotive vehicle has various kinds of electric instruments mounted thereon. Thus, the vehicle is arranged with wiring harnesses for supplying electrical signals and electrical powers to the instruments. Each wiring harness has a plurality of electrical cables and a plurality of connectors fitted to the electrical cables.
Particularly, an electric or hybrid car has electric instruments such as a motor and an electronic control unit. Each of the electric instruments has a case made of a synthetic resin material and various types of electronic components accommodated in the case. The electric instrument has a pin terminal fitted on the case for electrical connection with a wiring harness. The pin terminal is configured in a plate or a bar and has one end positioned in the case for electrical connection with on one of the electrical components and the other end positioned outside of the case for electrical connection with the wiring harness.
The wiring harness has a connector for electrical connection with the electric instrument. The connector has a receptacle terminal and a box-shaped connector housing accommodating the receptacle terminal.
For electrical connection of the electric instrument and the wiring harness, some types of connectors are used. One of them is disclosed in Japanese Patent Application Laid-open NO. H. 11-55892. As illustrated in FIGS. 9A and 9B, a prior art connector 100 has a connector housing 102 and a tab 101 attached therein. The tab 102 is made from an electrically conductive metal plate. The connector also has a junction terminal 103 accommodated in the connector housing 102.
The connector housing 102 is made of an insulating synthetic resin material to be defined in a box shape. The connector housing 102 has an engagement body 106 coupled with a case 105 of an electric instrument 104. The connector housing 102 also has a harness coupling portion (not shown) to engage with a connector of the wiring harness. The tab 101 has one end positioned in the engagement body 106 and the other end positioned within the harness coupling portion. The junction terminal 103 is accommodated in the engagement body 106 of the connector housing 102. The junction terminal 103 has a pair of female contact portions 107.
The female contact portion 107 has a bottom plate 108 and a pair of resilient contact pieces 109 each contiguous with each side end of the bottom plate 108. The female contact portion 107 pinches a pin terminal 110 or a tab 101 of the electric instrument 104 between the bottom plate 108 and the resilient contact pieces 109. The female contact portion 107 has the pair of resilient contact pieces 109 that press the pin terminal 110 or tab 101 against the bottom plate 108 so that the bottom plate 108 electrically connects with the pin terminal 110 or tab 101. That is, the resilient deformation of the female contact portion 107 can connect itself with the pin terminal 110 or tab 101.
Thus configured connector 100 accommodates the junction terminal 103 in the engagement body 106, and the female contact portion 107 of the junction terminal 103 electrically connects with an end of the tab 101. The engagement body 106 couples with the case 105 of the electric instrument 104, and the other of the female contact portions 107 of the junction terminal 103 electrically connects with the pin terminal 110 of the electric instrument 104. Furthermore, the harness coupling portion engages with a connector of the wiring harness, and the other end of the tab 101 electrically connects with a pin terminal of the wiring harness connector. Accordingly, the connector 100 electrically connects the electric instrument with the wiring harness electrically and mechanically.
The conventional connector 100 has three contact portions, one of which is between the pin terminal 110 of the electric instrument 104 and the female contact portion 107 of the junction terminal 103; a second one is between the female contact portion 107 of the junction terminal 103 and the tab 101; and a third one is between the tab 101 and a receptacle terminal of the wiring harness connector. In view of sure electrical connection, an increased number of contacts are disadvantageous.
The conventional connector 100 requires the tab 101 and the junction terminal 103 for electrical connection of the electric instrument 104 with the wiring harness, which increases parts in number. The connector 100 also needs a member for positioning and holding of the junction terminal 103 within the connector housing 102. The increase of parts causes an increased assembling man-hour, resulting in a higher manufacturing cost.
Furthermore, the connector 100 has the female contact portion 107 of the junction terminal 103 which resiliently deflects to electrically connect with the pin terminal 110 or tab 101. However, the female contact portion 107 of the junction terminal 103 may possibly deviate when the junction terminal 103 is engaged with the tab 101 within the connector housing 102. This is disadvantageous for sure electrical connection of the junction terminal 103 with the tab 101.
Particularly, when the connector 100 is used for a motor which is one of the electric instruments 104 to supply an electrical power to the motor for rotation thereof, a comparatively larger frictional force is needed between the female contact portion 107 of the junction terminal 103 and the tab 101. Thus, the connector 100 may possibly cause unreliable electrical connection between the female contact portion 107 and the tab 101.